The present invention relates to Internet telephone technologies and information processing techniques and more particularly to a technique effective to exclude illegal connection calls in an Internet telephone system.
In recent years, the Internet has been spread rapidly and it is recognized as information base in the community. From the viewpoint of reduction of costs of calling and a cost reduction attributable to unification of voice and data in individual enterprises, Internet telephone service is provided as the base of enterprise. An IP telephone in the Internet has been implemented with protocol such as H.323 and H.225RAS procedures. In originating a call from the IP (Internet Protocol) telephone in the Internet, authentication of the calling terminal and conversion of a destination telephone number into an IP address of a destination media gateway (address resolution) are carried out by means of a gate keeper and thereafter a call setup signal is transmitted from a VoIP (Voice over IP) gateway accommodating the IP telephone to the media gateway, thus achieving a call setup.